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by suction filtration and air-dried. The crude product (2a) was
obtained at 66% yield.
OCH3), 4.10 (s, 3H, CO2CH3), 7.06–9.13 (m, 8H, benzene and quin-
oline C–H). Anal. Calcd for C19H14F3NO3: C, 63.16; H, 3.905; N,
3.876. Found: C, 62.95; H, 4.175; N, 3.974.
5.1.2.2. Methyl 6-chloro-2-(4-methoxyphenyl) quinoline-4-car-
boxylate (3a). 6-Chloro-2-(4-methoxyphenyl) quinoline-4-car-
boxylic acid (2a) (0.98 g, 3 mmol) and potassium carbonate
(2.07 g, 15 mmol) were weighed into a round-bottom flask. Methyl
iodide (0.95 mL, 15 mmol) and acetone (4 mL) were added. The
reaction mixture was refluxed with magnetic stirring. The progress
of the reaction was monitored by TLC. The reaction was completed
after 5 h. The solvent was evaporated in vacuo and water was
added to the remaining mixture. The product was collected by suc-
tion filtration and air-dried. The crude product was separated on a
silica gel column to obtain pure 3a at 90% yield. mp: 169–170 °C; IR
5.1.2.10. Methyl 6-fluoro-2-(2-methoxybenzyl)quinoline-4-car-
boxylate (3i). White powder; 89%, 108–109 °C; IR (neat):
m
= 1723 cmÀ1 (C@O); 1H NMR (CDCl3): d = 3.86 (s, 3H, OCH3),
4.01 (s, 3H, CO2CH3), 4.41 (s, 2H, CH2), 6.89–8.43 (m, 8H, benzene
and quinoline C–H). Anal. Calcd for C19H16FNO3: C, 70.14; H, 4.957;
N, 4.305. Found: C, 70.26; H, 4.953; N, 4.332.
5.1.2.11. Methyl 6-fluoro-2-(4-methoxyphenyl)quinoline-4-car-
boxylate (3j). White powder; 86%, 119–120 °C; IR (neat):
m
= 1722 cmÀ1 (C@O); 1H NMR (CDCl3): d = 3.89 (s, 3H, OCH3),
(neat):
m
= 1721 cmÀ1 (C@O); 1H NMR (CDCl3): d = 3.90 (s, 3H,
4.06 (s, 3H, CO2CH3), 7.03–8.42 (m, 8H, benzene and quinoline
C–H). Anal. Calcd for C18H14FNO3: C, 69.45; H, 4.533; N, 4.499.
Found: C, 69.63; H, 4.476; N, 4.445.
OCH3), 4.08 (s, 3H, CO2CH3), 7.03–8.79 (m, 8H, benzene and quin-
oline C–H). Anal. Calcd for C18H14ClNO3: C, 65.96; H, 4.305, N,
4.273. Found: C, 65.89; H, 4.304, N, 4.239.
Compounds 3b–o were synthesized by a similar method. The
data are listed below:
5.1.2.12. Methyl 3-benzyl-6-fluoro-2-methylquinoline-4-car-
boxylate (3k). White powder; 80%, 122–123 °C; IR (neat):
m
= 1730 cmÀ1 (C@O); 1H NMR (CDCl3): d = 2.58 (s, 3H, 3-CH3),
5.1.2.3. Methyl 6-chloro-2-phenethylquinoline-4-carboxylate
3.99 (s, 3H, CO2CH3), 4.17 (s,2H, CH2), 7.09–8.06 (m, 8H, benzene
and quinoline C–H). Anal. Calcd for C19H16FNO2: C, 73.77; H,
5.213; N, 4.528. Found: C, 73.88; H, 5.140; N, 4.524.
(3b). White powder; 92%, 90–91 °C; IR (neat):
m = 1721 cm
À1(C@O); 1H NMR (CDCl3): d = 3.18 (t, 2H, CH2), 3.32 (t, 2H, CH2),
4.03 (s, 3H, CO2CH3), 7.20–8.79 (m, 9H, benzene and quinoline
C–H). Anal. Calcd for C19H16ClNO2: C, 70.04; H, 4.949, N, 4.299.
Found: C, 70.04; H, 4.922; N, 4.315.
5.1.2.13. Methyl 6-fluoro-2-phenethylquinoline-4-carboxylate
(3l). White powder; 87%, 64–65 °C; IR (neat):
m
= 1723 cmÀ1
(C@O); 1H NMR (CDCl3): d = 3.18 (t, 2H, CH2), 3.31 (t, 2H, CH2),
4.02 (s, 3H, CO2CH3), 7.20–8.50 (m, 9H, benzene and quinoline
C–H). Anal. Calcd for C19H16FNO2: C, 73.77; H, 5.213; N, 4.528.
Found: C, 73.95; H, 5.148; N, 4.511.
5.1.2.4. Methyl 6-chloro-3-phenyl -2- methylquinoline-4-car-
boxylate (3c). White powder; 91%, 141–142 °C; IR (neat):
m
= 1731 cmÀ1 (C@O); 1H NMR (CDCl3): d = 2.40 (s, 3H, 3-CH3),
4.11 (s, 3H, CO2CH3), 7.26–8.10 (m, 8H, benzene and quinoline
C–H). Anal. Calcd for C18H14ClNO2: C, 69.35; H, 4.526; N, 4.493.
Found: C, 69.03; H, 4.557; N, 4.433.
5.1.2.14. Methyl 7-fluoro-1,2,3,4-tetrahydroacridine-9-carbox-
ylate; white powder (3m). 80%, 91–92 °C; 1H NMR (CDCl3):
d = 1.90 (m, 2H, CH2), 1.98 (m, 2H, CH2), 2.94 (t, 2H, CH2), 3.15 (t,
2H, CH2), 4.06 (s, 3H, CO2CH3), 7.26–8.00 (m, 3H, acridine C–H).
Anal. Calcd for C15H14FNO2: C, 69.49; H, 5.442; N, 5.402. Found:
C, 69.69; H, 5.431; N, 5.396.
5.1.2.5. Methyl 3-benzyl-6-chloro-2-methylquinoline-4-carbox-
ylate (3d). White powder; 87%, 141–142 °C; IR (neat):
m
= 1731 cmÀ1 (C@O); 1H NMR (CDCl3): d = 2.58 (s, 3H, 3-CH3),
3.98 (s, 3H, CO2CH3), 4.16 (s, 2H, CH2), 7.08–8.04 (m, 8H, benzene
and quinoline C–H). Anal. Calcd for C19H16ClNO2: C, 70.04; H,
4.949; N, 4.299. Found: C, 70.01; H, 4.876; N, 4.196.
5.1.2.15. Methyl 3-benzyl-6-methoxy-2-methylquinoline-4-car-
boxylate (3n). White powder; 80%, 122–123 °C; 1H NMR (CDCl3):
d = 2.54 (s, 3H, 2-CH3), 3.91 (s, 3H, OCH3), 3.95 (s, 3H, CO2CH3),
4.15(s, 2H, CH2), 6.95–7.97 (m, 8H, benzene and quinoline C–H).
Anal. Calcd for C20H19NO3: C, 74.75; H, 5.959; N, 4.358. Found: C,
74.78; H, 5.957; N, 4.275.
5.1.2.6. Methyl 6-chloro-2-(2-methoxybenzyl)quinoline-4-car-
boxylate (3e). White powder; 85%,113–114 °C;IR (neat):
m
= 1730 cmÀ1 (C@O); 1H NMR (CDCl3): d = 3.82 (s, 3H, OCH3),
3.98 (s, 3H, CO2CH3), 4.38 (s, 2H, CH2), 6.90–8.74 (m, 8H, benzene
and quinoline C–H). Anal. Calcd for C19H16ClNO3: C, 66.76; H,
4.718; N, 4.097. Found: C, 66.82; H, 4.603; N, 4.027.
5.1.2.16. Methyl 6-methoxy-2-phenethylquinoline-4-carboxyl-
ate (3o). White powder; 87%, 121–122 °C; 1H NMR (CDCl3):
d = 3.15 (m, 2H, CH2), 3.30 (m, 2H, CH2), 3.96 (s, 3H, OCH3), 4.01
(s, 3H, CO2CH3), 7.20–8.19 (m, 9H, benzene and quinoline C–H).
Anal. Calcd for C20H19NO3: C, 74.75; H, 5.959; N, 4.358. Found: C,
74.91; H, 5.937; N, 4.329.
5.1.2.7. Methyl 7-chloro-1,2,3,4-tetrahydroacridine-9-carboxyl-
ate (3f). White powder; 70%, 110–111 °C; 1H NMR (CDCl3):
d = 1.89 (m, 2H, CH2), 1.98 (m, 2H, CH2), 2.93 (t, 2H, CH2), 3.14
(t, 2H, CH2), 4.07 (s, 3H, CO2CH3), 7.27–7.94 (m, 3H, acridine
C–H). Anal. Calcd for C15H14ClNO2: C, 65.33; H, 5.117; N, 5.079.
Found: C, 65.45; H, 5.252; N, 4.754.
5.1.3. General procedure for the preparation of compounds 2p–
v; example
5.1.3.1.
2-(4-Pentyloxyphenyl)quinoline-4-carboxylic acid
5.1.2.8.
Methyl
1,2,3,4-tetrahydroacridine-9-carboxylate
(2u). 4-hydroxybenzaldehyde (1.22 g, 10 mmol) dissolved in
DMF (10 mL), potassium hydroxide (0.731 g, 12 mmol) was added.
After the reaction mixture was stirred at 120 °C for about 1 h, 1-
bromopentane 1.87 mL (15 mmol) was added, then stirred at
120 °C (monitored by TLC). The reaction was completed about
5 h. The solution was cooled, poured into water, and extracted with
CHCl3 three times. The combined organic extracts, dried over
Na2SO4, and concentrated in vacuo. 4-(pentyloxy)benzaldehyde
crude product was used to next step without purfication.Under
(3g). White powder; 72%, 77–78 °C;1H NMR (CDCl3): d = 1.90
(m, 2H, CH2), 1.99 (m, 2H, CH2), 2.94 (t, 2H, CH2), 3.16 (t, 2H,
CH2), 4.05 (s, 3H, CO2CH3), 7.27–8.02 (m, 3H, acridine C–H). Anal.
Calcd for C15H15NO2: C, 74.67; H, 6.266; N, 5.805. Found: C,
74.66; H, 6.116; N, 5.810.
5.1.2.9. Methyl 2-(4-methoxyphenyl)-6-(trifluoromethyl)quino-
line-4-carboxylate (3h). White powder; 80%, 117–118 °C; IR
(neat):
m
= 1723 cmÀ1 (C@O); 1H NMR (CDCl3): d = 3.88 (s, 3H,